Answer: Rubber Bands
The majority of office supplies you come across on a day-to-day basis were expressly invented for the purposes you use them. Correction fluid, such as the best-selling brand Liquid Paper, was invented in the early 1950s by secretary Bette Nesmith Graham specifically for the task we all use it for: covering up mistakes on paper. The same can be said of staples and paper clips, two different kinds of paper fasteners that were, well, invented to fasten things to paper (including paper to itself).
Rubber bands, on the other hand, were an invention looking for an application. Early applications of rubber-band like designs, such as rings of rubber elastic-like material in garters and waistbands, first appeared in the early 19th century. The rubber used in these designs, however, wasn’t particularly stable and prone to damage from hot or cold. Despite the abundance of waste rubber from early rubber manufacturing and the willingness of early inventors and entrepreneurs to capitalize on this waste in making all manner of things (including early rubber bands), they just didn’t catch on.
The primary reason was instability and brittleness. This issue was resolved when, in 1839, Charles Goodyear discovered rubber vulcanization and revolutionized rubber production. Several years later in 1845, English inventor Stephen Perry patented rubber bands made from vulcanized rubber and, finally, the rubber band had evolved to the point that it could become a practical office staple.